diff --git a/src/visualization.jl b/src/visualization.jl
index d36205e..5ba8699 100644
--- a/src/visualization.jl
+++ b/src/visualization.jl
@@ -68,13 +68,13 @@ function starting_points!(U, V)
     jitter = 5
     margin = radius + 2
     rels = [
-        (1/4, 1/4), (3/4, 1/4), (1/2, 1/2),
-        (1/4, 3/4), (3/4, 3/4), (1/2, 1/8)
+        (1 / 4, 1 / 4), (3 / 4, 1 / 4), (1 / 2, 1 / 2),
+        (1 / 4, 3 / 4), (3 / 4, 3 / 4), (1 / 2, 1 / 8)
     ]
     for (px, py) in rels
         cx = clamp(round(Int, px * N) + rand(-jitter:jitter), margin, N - margin)
         cy = clamp(round(Int, py * N) + rand(-jitter:jitter), margin, N - margin)
-        for x in (cx - radius):(cx + radius), y in (cy - radius):(cy + radius)
+        for x in (cx-radius):(cx+radius), y in (cy-radius):(cy+radius)
             if 1 ≤ x ≤ N && 1 ≤ y ≤ N && hypot(x - cx, y - cy) ≤ radius
                 U[x, y] = 0.50
                 V[x, y] = 0.25
@@ -86,7 +86,7 @@ end
 function param_box!(grid, row, labeltxt, observable::Observable)
     Label(grid[row, 1], labeltxt)
     box = Textbox(grid[row, 2], validator=Float64, width=50,
-                  placeholder=labeltxt, stored_string="$(observable[])")
+        placeholder=labeltxt, stored_string="$(observable[])")
     on(box.stored_string) do s
         try
             observable[] = parse(Float64, s)
@@ -108,8 +108,9 @@ function build_ui(U, V, Du, Dv, F, k, params_obs, heat_obs)
 
     run_label = Observable("Run")
     stepsize = Observable(30)
+    spoint = select_point(ax.scene)
 
-    # Controls
+    # # Controls
     fig[2, 1] = buttongrid = GridLayout(ax.scene, tellwidth=false)
     btn_step = Button(buttongrid[1, 1], width=60, label="Step")
     btn_start = Button(buttongrid[1, 2], width=60, label=run_label)
@@ -117,8 +118,8 @@ function build_ui(U, V, Du, Dv, F, k, params_obs, heat_obs)
     btn_Jaguar = Button(buttongrid[1, 4], width=60, label="Jaguar")
 
     slidergrid = SliderGrid(fig[3, 1], (label="Speed", range=1:100,
-                                       format="{}x", width=350,
-                                       startvalue=stepsize[]))
+        format="{}x", width=350,
+        startvalue=stepsize[]))
     speed_slider = slidergrid.sliders[1].value
 
     gh[1, 2] = textboxgrid = GridLayout(ax.scene, tellwidth=false)
@@ -156,15 +157,16 @@ function build_ui(U, V, Du, Dv, F, k, params_obs, heat_obs)
     end
 
     on(btn_Jaguar.clicks) do _
-        
+
         Du[] = 0.142
         Dv[] = 0.078
-        F[]  = 0.0617
-        k[]  = 0.062
+        F[] = 0.0617
+        k[] = 0.062
 
         if !running[]
             running[] = true
-            U .= 1.0; V .= 0.0
+            U .= 1.0
+            V .= 0.0
             @async while running[]
                 multi_step!((U, V), stepsize[], heat_obs, params_obs)
                 sleep(0.0015)
@@ -179,7 +181,27 @@ function build_ui(U, V, Du, Dv, F, k, params_obs, heat_obs)
         running[] = false
         reset!(U, V, heat_obs)
     end
+    on(spoint) do pt
+        r = 5
+        if pt === nothing
+            return
+        end
+        x, y = pt
+        println("params_obs[].N, ", params_obs[].N)
+        i, j = coord_to_index(x, y, params_obs[].N)
 
+        # get corners of square that will get filled with concentration
+        imin = max(i - r, 1)
+        imax = min(i + r, params_obs[].N)
+        jmin = max(j - r, 1)
+        jmax = min(j + r, params_obs[].N)
+
+        # set disbalanced concentration of U and V
+        U[imin:imax, jmin:jmax] .= 0.5
+        V[imin:imax, jmin:jmax] .= 0.25
+
+        heat_obs[] = copy(U)
+    end
     return fig
 end